Knob attachment



(No ModeL F. H.-RICHARDS. KNOB ATTAGHMENT.

No. 530,624. Patented Dec. 11, 1894 UNITED STATES PATENT OFFICE.

FRANCIS H. RICHARDS, OFiHARTFORD, CONN ECIICUT.

KNOB ATTACH'M ENT.

SPECIFICATION forming part of Letters Patent No. 530,624, dated December 11, 1 894.

Application filed June 9, 1893. SerialNo. 477,058. (Nomodeh) To all whom it may concern.-

Be it known that I, FRANCIS H. RICHARDS,

"a citizen of the United States, residing-at Hartford, in the county of Hartford andState of Connecticut, have invented certain new and useful Improvements in Fastening Devices, of which the following is a specification.

This invention relates to that class of attachments or clam ping-couplings adapted for removably fixing hubs, knobs and like parts to spindles or like rods by means of clampingdevices; the object being to provide a simple and powerful two-part fastening-device in which the hub or stem'constitutes the spindleclamp, and in which the clamp-sleeve has no longitudinal movement relative to the other parts during the operation of securing the hub or stem in its proper position upon the spindle.

When my improvement is applied to the stem of a door-knob, this may be placed with the end of its clamp-sleeve or stem closely against the escutcheon or bearing-plate upon the door, and then rigidly fixed in place without any longitudinal movement of any part thereof relatively to the spindle. At the same time the separate spindle-clamp heretofore generally used in this class of knob-attachments is dispensed with, and a knob-fastening is produced which is simple and durable in construction, effective in its operation, and of low cost to manufacture.

In the drawings accompanying and forming a part of this specification, Figure 1 is a vertical longitudinal section of a door-knob furnished with my improvements, the view being taken online 11 of Fig. 2, and the usual squared spindle being shown in side elevation. Fig. 2 is an end view of the knob-attachment looking from the right-hand in Fig.

1. Fig. 3 is a side elevation of the knob-stem. Fig. 4 is an end view of the same looking from the right-hand of Fig. 3, a portion of the knob being broken away. Fig. 5 is a side elevation of the clamp-sleeve. Fig. 6 is an end View of the same. Fig. 7 is a longitudinal section of said sleeve, and Fig. 8 an enlarged sectional detail of the spindle, knob-stem and clampsleeve taken on line 8-8, Fig: 1.

Similar characters designate like parts in all the figures.

The spindle S is, or may be, as shown in the drawings, of the usual squared cross-sectional I formand of uniform diameter throughout the length thereof. The hub or stem 6 of the knob K- is shown having a suitable central opening and should be fitted to slide freely and closely upon the spindle S. Said stem should also have formed thereon, as herein shown, peripherally thereof, a suitable number of inclined or.wedge-like bearing-faces or steps, 9, the planes of the bearing-faces'of one wall spirally coinciding with those of the other wall, and forming together a continuous inclined spiral path or wedge, which preferably-occupies a considerable portion of the length of the hub. Said bearing-faces of the hub or stem are adapted" to be engaged by the similar but reversely-arranged bearing-faces, 10, formed upon the interior of the thimble or clampsleeve 8. For assembling the fastening-device, said clamp-sleeve is turned upon the knob-stem, after the manner of putting a nut on a bolt, until the sleeve rests against the stop-shoulder 12, this operation being performed prior to the placing of the knob on the-spindle. The bearing-faces 9 upon the stem and the bearing-faces 10 within the sleeve are relatively'so formed as to closely intermesh, and so that the sleeve may still be readily turned for assembling and disassembling the parts.

In assembling the parts and securing the knob-stem on the spindle, the clamp-sleeve'is first placed upon the stem inloose engagement with the abutment or shoulder 12,-the outer'end of'said clamp being, when in this position, preferably flush with the outerend of the stem, as clearly shown in-Fig. 1. At this time the walls of the stem are not compressed, and said stem is in a condition to be freely slid lengthwise of the spindle. The knob-stem being now placed upon the spindle in the required position, the clamp-sleeve will be forcibly turned forward (usually by means of a wrench engaginga hexagonal orsquared portion, 13, :thereof) in the proper direction, as indicated, for instance, by the arrow shown in Fig. 2. This will force the abutting end 11 against the abutment 12 of the stem, (said abutment preventing any forward longitudinal movement of the sleeve with relation to the stem,) and, by the reaction of said force, cause the wedge-like bearing-faces 10 of said sleeve to ride upward upon the inclined bearing-faces 9 as shown by the dotted line-21 in Fig. 3, thereby compressing or closing together the yielding walls 6, 6" of the stem. This lateral or closing movement of the said walls is, of course, proportionate to the rotary movement of the sleeve, having regard to the differences in the pitch of the bearing-faces in the circular path of travel of said sleeve.

The hub or stem being rigidly closed upon the spindle by so powerful a Wedge-device as described, is securely held against either lateral or longitudinal movement on the spindle, and with the clamp-sleeve forms a simple and efiective knob-attachment, in which there is no longitudinal movement whatever of any part upon or relatively to the spindle during the operation of fastening and unfastening the hub or stem to and from the rod or spindle. This is an important desideratum, since it permits the hub or stem to be first accurately adjusted to its exact position, and then to be firmly secured in place, without any allowance being made for the longitudinal movement of any of the parts. Heretofore such an allowance has generally been necessary for properly placing door-knobs upon their spindles when these are in the door ready for use. This feature obviates the necessity for' using any rose, or tongue-and groove devices, to cover the joints of the structure.

The described construction of the fastening-device results in a very rigid, compact and powerful knob-stem and attachment, with no parts to become loose and rattle, and having all the requirements of a first-class arti cle. At the same time, the construction is such that the fastening-device may be easily manufactured by simple, well-known and inexpensive means and methods, thereby producing a device of superior character at a low cost.

When the spindle is of an angular crosssectional form as shown in the drawings, and is smaller than thebore of the stem, this in closing is forced into a slightly irregular external shape, so that its peripheral lines are not truly circular. For accommodating this deviation and to effect a proper distribution of the pressure over the spindle surfaces within the stem, the sleeve is made of small thickness relatively to the diameter thereof, so that it will, when forcibly tightened, readily conform in cross-sectional shape to the irregularities of the closed stem, and thereby maintain the perfect coaction of the several parts of the fastening. In practice, also, the sleeve, by reason of its relatively small thickness, and being of elastic metal (preferably bronze), expands somewhat, and thus overcomes the eifect of any slight differences in the shape and size of the spindle at different points in the length thereof.

The diametrical inclination, indicated by the dotted line 20, Fig. 1, of the wedge-faces relatively to the spindle, should correspond substantially with the normal angle ofrepose, or come within about the minimum and maximum limits of five and twenty-five degrees, respectively, from said spindle, or from the axis of the stern. In practice, I prefer said angle should be about ten degrees, substantially as shown in the drawings, and that the wedge-faces should be one-eighth to onesixth of an inch wide, for use in knob-fastenings of ordinary sizes.

I do not limit myself to the use of a hub or stem having two yielding walls 6, 6", since it is obvious that said stem may be slitted to form three or more yielding walls, or may have only one slit, and consequently only one such wall. The construction shown, however, is deemed preferable, the slits 5 being, preferably, where an angular spindle is used, in alignment with the plane of the opposite angles or cornersof said spindle. Neither is my invention limited to the use of a spindle that is square, or of any particular angular cross-section, for a round spindle may be used if desired.

Having thus described my invention, I claim- The herein-described two-part fasteningdevice for knobs, it consisting of a compressible tubular stem bored to receive a spindle and having on the compressible portion thereof inclined wedge-bearings, substantially as described, and havinga fixed clamp-sleeve abutment, combined with a clamp-sleeve having internal inclined bearings adapted for engagingwith the bearings of the stem, and having its inner end in engagement with said abutment, and adapted to be turned for compressing the stem, substantially as described.

FRANCIS H. RICHARDS.

Witnesses:

FRED. J. DOLE, JOHN L. EDWARDS, Jr. 

